I lead a project built on Deno; it was not my call, just to be clear. Deno turned out unfortunately to be a miss and we had seen the writing on the wall. FWIW, we're moving to a much bigger Rust core program with node for JS user extensibility. (In other words, I'm not willing to risk using the deno_core crates.)

The one silver lining here is that Deno had already increased their node/npm compatibility. Migrating off of the jsr ecosystem and back to npm is going to be less painful than one might imagine. I expect present LLMs to be sufficiently good at the task, for example.